This invention relates to a switch device and more particularly, to improvements over the switch devices as disclosed in Japanese Utility Model Registration Nos. 843,881 and 979,805.
Any of the device disclosed in the above-mentioned Japanese utility model registrations comprises a slidable member adapted to move in response to the pivotal movement of an accelerator pedal by the application of a depressing-down force to the pedal or the release of the depressing-down force applied to the pedal to thereby operate a movable contact operation member to cause a movable contact to make engagement with or disengage from a cooperating stationary contact and after the slidable member has moved a predetermined amount to operate the movable pad operation member, the slidable member moves leaving the movable pad member inoperative with the movable contact maintained in engagement with or disengagement from the cooperating stationary contact. As soon as the depressing-down force applied to the accelerator pedal is removed from the pedal, the movable contact makes engagement with or disengages from the cooperating stationary contact.
Assuming that any of the switch devices of the above-mentioned Japanese utility model registrations is so designed that when the accelerator pedal is depressed down while the motor car in which the switch device is incorporated is running, the electrical contacts make engagement with each other and when the depressing-down force applied to the pedal is removed from the pedal, the electrical contacts separate from each other or alternatively, when the depressing-down force applied to the accelerator pedal is removed from the pedal, the electrical contacts make engagement with each other and when the depressing-down force is applied to the pedal, the electrical contacts separate from each other.
In some instances the switch devices of the above-mentioned Japanese utility model registrations are so designed that when the accelerator pedal is depressed-down, the electrical contacts of the switch device make engagement with each other to make the electric circuit from the power source to the electromagnet to supply electric current to the electromagnet to thereby retract the metering rod out of the main jet bore in the main jet control device incorporated in the carburetor of a motor car engine so as to increase the ratio of fuel in the fuel-air mixture within the engine whereby the motor car is accelerated. When the motor car has been accelerated to a desired speed, the depressing-down force applied to the accelerator pedal is released to separate the electrical contacts from each other whereupon the metering rod is advanced into the main jet bore to limit the flow of fuel to the engine, that is, the fuel ratio in the fuel-air mixture within the engine is decreased.
There is also the instance in which the switch devices are so designed that when the depressing-down force applied to the accelerator pedal is released, the electrical contacts make engagement with each other. In such a case, since the release of the depressing down force applied to the accelerator pedal is to decelerate the motor car, the closure of the electric circuit to the electromagnet through the engagement between the electrical contacts allows electric current to flow to the electromagnet to advance the metering rod so as to close the main jet bore whereby the flow of fuel to the engine is interrupted. Thus, in the latter case, waste of the fuel is prevented to decrease the environmental pollution accordingly.
Assuming that the brake pedal is depressed down either to accelerate or stop a motor car which is running at a deceleration, then, since the contacts are in engagement with each other and the main jet bore is closed to interrupt the flow of fuel to the engine at such at time as in the former instance, the engine tends to stop. Therefore, it is necessary to separate the contacts from each other and resume the flow of fuel to the engine. In order to accelerate the motor car, the accelerator pedal is depressed-down and the metering rod is retracted out of the main jet bore to open the main jet bore whereby the fuel is passed into the engine to operate the engine satisfactorily. However, when the motor car is stopped, since the accelerator pedal is not depressed-down, the contacts remain in their engaging position. In order to overcome the difficulties inherent in the conventional switch devices, it has been practiced that the brake pedal, clutch pedal and gear lever are provided with separate switches to operate the pedals separately to open the contacts associated with these switches, respectively. These separate switches are connected in series to each other and to any of the switch devices disclosed in the above-mentioned Japanese utility model registrations to thereby prevent the stoppage of the engine when the running motor car is stopped.